Outboard motor trolling muffler



N 1966 M. R. GAZZARA 3,282,373

OUTBOARD MOTOR TROLLING MUFFLER Filed July 15, 1965 2 Sheets-Sheet 1 Fig.

Matthew R. Gazzara INVENTOK BY WWW Nov. 1, 1966 M. R. GAZZARA 3,

OUTBOARD MOTOR TROLLING MUFFLER Filed July 15. 1965 2 Sheets-Sheet 2 Fig. 5

/8 Matthew R. Gazzara 1N VENTOR.

BY WW 3% United States Patent M 3,282,373 OUTBOARD MOTOR TROLLING MUFFLER Matthew R. Gazzara, 345 White Horse Pike, Hammonton, NJ. Filed July 15, 1965, Ser. No. 472,217 11 Claims. (Cl. 181-39) This invention relates to a novel and useful attachment for outboard drive assemblies of the type including a depending power leg having a horizontally and outwardly projecting cavitation flange adjacent its lower end and a downwardly and rearwardly projecting exhaust outlet projecting below the rear end portion of the cavitation flange, The trolling muffler of the instant invention is adapted to be removably supported from the depending power leg of an outboard drive assembly and opertively associated therewith in a manner such that both engine exhaust being discharged from the exhaust outlet of the engine and portions of the ambient water will enter and be mixed together in the trolling muffler and thereafter discharged above the surface of the 'body of water in which the exhaust outlet is disposed.

The trolling mufiler of the instant invention comprises an upstanding tubular member which is to be mounted rearwardly of the associated power leg and which terminates at its lower end portion in a forwardly opening and directed open end portion supportingly engaged with the exhaust outlet and the cavitation flange of the power leg disposed immediately above the exhaust outlet. The trolling muffler may be substantially vertically disposed or somewhat inclined rearwardly and upwardly. Further, by mixing ambient water with the engine exhaust gases before the latter are discharged from the mufiier the sound waves of the exhaust are reduced in sharpness and therefore when the exhaust is discharged above the surface of the ambient water, the portion of the noise of the original exhaust transmitted to the ambient Water is greatly reduced. The open forward end of the lower end portion of the tubular member has a configuration adapting it to form a relatively tight seal between the trolling muffler and the adjacent portions of the power leg. If there is a small amount of seepage of additional water into the mufiler between the confronting surfaces of the outboard drive assembly and the trolling muffler, the rapid movement of exhaust gases through the trolling mufiier during operation of the associated motor will cause this seepage to be blown outwardly from the top of the trolling muffler.

The main object of this invention is to provide a trolling muffler for an outboard drive assembly and which is operable to duct the exhaust gases from the associated motor to a point above the surface of the associated body of water in order that the transmission of the pressure impulses and noise of the exhaust gases to the associated body of water will 'be greatly reduced. In this manner, fish within the associated body of water will not be as readily disturbed .and will be more susceptible to striking at a lure or baited hook.

Another object of this invention, in accordance with the immediately preceding object, is to provide a trolling muffler which may be readily atached to various types of existing outboard drive assemblies.

Still another object of this invention is to provide a trolling motor including structural features which may be really modified during manufacture so as to adapt the trolling muffler for use in connection with substantially all types of outboard drive assemblies including the aforementioned exhaust outlet and cavitation flange.

Yet another object of this invention is to provide a trolling muifler that may be readily attached to an exist- 3,282,373 Patented Nov. 1, 1956 ing outboard drive assembly without appreciably increasing the drag of the associated body of water on the modified outboard drive assembly.

Another object of this invention is to provide a trolling muflier in accordance with the preceding objects and including means by which the exhaust gases directed thereinto may be selectively discharged either below the surface of the associated body of water or above said surface.

An ancillary object of this invention is to provide an outboard drive assembly trolling mufiier in accordance with the preceding objects and constructed in a manner where-by it may be readily modified so as to be semipermanently secured to the associated outboard drive assembly or readily removably secured to the associated outboard drive assembly.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view of the lower portion of a conventional form of outboard motor shown with one form of the trolling mufiier operatively supported therefrom and shown in longitudinal vertical section;

FIGURE 2 is a perspective view of the trolling muffler illustrated in FIGURE 1;

FIGURE 3 is a horizontal sectional view taken substantially upon the plane indicated by the section line 3-3 of FIGURE 1;

FIGURE 4 is a side elevational view similar to FIG- URE 1 but showing a modified form of trolling muffler;

FIGURE 5 is a fragmentary side elevational view similar to FIGURES 1 and 4 and showing a still further modified form of trolling mufiier secured thereto and shown in vertical section; and

FIGURE 6 is yet another fragmentary side elevational view similar to FIGURE 5 but illustrating movable portions of the trolling muffler illustrated therein in different positions of operation.

Referring now more specifically to the drawings, the numeral 10 generally designates a conventional outboard motor which includes a depending drive assembly generally referred to by the reference numeral 12. The drive assembly 12 includes an upstanding housing 14 from whose lower end a marine propeller 16 is rotatably journalled. In addition, the housing 14 includes a laterally outwardly and generally horizontally disposed cavitation flange 18 which extends substantially entirely about one lower end portion of the housing 14. Still further, the housing 14 includes a rearwardly and downwardly inclined exhaust outlet nozzle 20 which projects below the rear portion of the cavitation flange 18.

The trolling mufiier of the instant invention is generally referred to by the reference numeral 22 and includes an upstanding tubular member 24 which is generally rectangular in horizontal plan including a pair of opposite side walls 26 and 28 interconnected at their forward ends by means of a front wall 30 and the rear ends by means of a semi-cylindrical rear wall 32. The lower end of the tubular member 24 has a lower terminal end portion secured thereto which is generally U-shaped in configuration and designated in general by the reference numeral 34. The terminal end portion 34 includes a pair of opposite side walls 36 and 38 interconnected by a rearwardly and upwardly inclined generally semi-cylindrical bottom wall 40 and it may be seen from a comparison of FIG- URES 1 and 2 of the drawings that the forward end of the bottom wall 40 is turned up as at 42 and that the forward terminals ends of the side walls 36 and 38 are forwardly convergent as at 44 and 46. Further, the upper edges of the forward portions of the side walls 36 and 38 terminate in apertured mountings flanges 48 and 50 while the rear end portions 52 of the side walls 36 and 38 are secured to corresponding lower end portions of the side walls 28 and 26 in any convenient manner such as by spot welding or fasteners 54, the terminal ends 44 and 46 being bevelled at 55.

With attention now invited more particularly to FIG- URE 1 of the drawings, it may be seen that the upturned and forwardly convergent portions of the bottom wall 40 and the side walls 36 and 38 snugly embrace the outlet end of the exhaust outlet nozzle 20 and that the apertured flanges 48 and 58 underlie the adjacent portions of the cavitating flange 18 and are secured thereto by means of suitable fasteners 56.

In operation, as the outboard motor is moving at slow speeds, the exhaust being discharged from the exhaust outlet nozzle 20 will enter the open forward end of the terminal end portion 34 and thereafter be directed upwardly through the tubular member 22. However, it will be noted that the side wall 26 of the tubular member 24 has a small weep hole 58 formed therein through which small quantities of water may enter the trolling muffler 22 in order to provide a sound muffling effect within the trolling muffler 22.

With attention now invited. more specifically to FIG- URE 4 of the drawings there will be seen a modified form of trolling muflier generally referred to by the reference numeral 22 and which is substantially identical to the trolling mufller 22 except that it is formed from one single .piece of material and the front wall 30 thereof is disposed further forward over the open end of the lower terminal end portion 34' and includes a rearwardly and downwardly directed portion 33 which overlies and conforms to a rearwardly and downwardly inclined surface 35 of the outboard motor 10 disposed above the cavitation flange 18. The trolling motor 22 includes forwardly and upwardly inclined portions 42 and forwardly convergent portions 44' and 46' corresponding to the portions 42 and 44 and 46 and is removably secured on the housing 14 by means of an expansion spring 60 having one end secured to the upper portion of the rear wall 24 and the other end secured to the housing 14 as at 62 at a point disposed above the upper end of the tubular member 24'. In addition, if a stronger expension spring were utilized. and such a stronger spring were of a shorter length, it could be secured between the point 62 and the upper end of the front wall 30'.

With attention now invited more specifically to FIG- URES 5 and 6 of the drawings, there will be seen a trolling muffler which is quite similar to the trolling muffler 22 in configuration but which is generally referred to by the reference numeral 22". The configuration of the trolling muffler 22" is substantially identical to the trolling mufller 22 except that the terminal end portion 34 thereof includes mounting flanges 64 which are substantially identical to the mounting flanges 48 and and which are secured to the cavitation flange 18 by means of suitable fasteners 66. In addition, the tubular member 24" of the trolling mufller 22" includes an outlet opening 68 in lieu of the rearwardly and upwardly inclined portion '78 of the rear wall of the trolling mufller 22 and a vertical swingable flap valve member 72 is hinged as at 74 for movement between the positions illustrated in FIGURES 5 and 6 of the drawings to cause the exhaust from the outboard motor 10 to be ducted above the surface of the associated body of water and be discharged below said surface, respectively. The flap valve member 72 has an operating rod 76 operatively connected thereto and the upper end of the operating rod 76 is slidably received through a clamp assembly 78 supported from the power head portion 88 of the outboard motor 10 and may be held. in adjusted vertically shifted position by means of a set screw '82 carried by the clamp assembly 78. Accordingly, it may be seen that the flap valve member 72 may be shifted between a position closing the outlet opening 68 in order that the exhaust from the motor 10 will be ducted upwardly through the tubular member 24" of the trolling mufller 22" and a position opening the outlet opening 68 and terminating communication between the upper portion of the tubular member 24" and the lower terminal end portion 34."

The trolling mulflers 22' and 22," each include small weep holes corresponding to the weep hole or opening 58 of the trolling mufller 22 and accordingly it may be seen that the operation of the trolling muflier 22' is substantially identical to the operation of the trolling mufller 22 and that the operation of the trolling muffler 22" is substantially similar except that it is operable to adjustably discharge the exhaust of the associated motor either above the surface of a corresponding body of water or below said surface.

The trolling mufller 22 may also be constructed without the forward terminal ends 44 and 46 of the side walls 36 and 38 which embracingly receive therebetween the open rear end of the exhaust outlet nozzle 20. In this instance, the front edges of the side walls 36 and 38 will abut the rearwardly facing end edges of the nozzle 20.

Further, the mufller 22 can be made as an integral portion of the housing 14 or permanently secured to the latter as desired.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.

What is claimed as new is as follows:

1. In combination with an outboard drive assembly of the type including a depending power leg having a horizontally outwardly end rearwardly projecting cavitation flange adjacent its lower end, a downwardly and rearwardly projecting exhaust outlet projecting below the rear end portion of said cavitation flange, a trolling muffler attachment comprising an upstanding tubular member disposed rearwardly of said power leg and terminating at its lower end portion in a forwardly opening and directed open end portion supportingly engaged with said exhaust outlet and said cavitation flange so as to form a continuation of said exhaust outlet, said tubular member projecting above the normal water level on said power leg.

2. The combination of claim 1 wherein said forwardly directed end portion includes generaly horizontal flange portions disposed in lapped relation with and secured to said cavitation plate.

3. The combination of claim 2 wherein said flange portions are disposed in underlying engagement with said cavitation flange.

4. The combination of claim 1 wherein the lowermost portions of the forward terminal end portion of said forwarwdly directed end portion are forwardly and upwardly inclined and hooked over the corresponding rear portions of the lower end of said exhaust outlet.

5. The combination of claim 1 wherein said tubular member includes at least one weep opening disposed below said water level and above said cavitation flange.

6. The combination of claim 1 wherein said exhaust outlet includes rearwardly diverging side walls, the side walls of said open end portion including forwardly convergent forward terminal ends embracingly engaging said rearwardly diverging side walls therebetween.

7. The combination of claim 6 wherein said open end portion includes a forwardly and upwardly inclined forward terminal end portion underlying and embracing the 'rearmost lower end of said exhaust outlet.

8. The combination of claim 1 wherein said power leg includes a rearwardly and downwardly inclined rearwardly facing surface terminating at its lower end at said cavitation flange, said tubular member including a similarly inclined forwardly facing surface disposed in surface to surface abutting engagement with said rearwardly facing surface.

9. The combination of claim 8 including an expansion spring secured at one end to an upper portion of said tubular member and at its other end to an upper portion of said drive assembly disposed forwardly of said tubular member.

10. The combination of claim 1 wherein the rear end of said forwardly directed portion has a rearwardly opening exhaust outlet opening formed therein, and a movable valve member suported in said tubular member and shift- References Cited by the Examiner UNITED STATES PATENTS 3,124,097 3/1964 Priddle.

RICHARD B. WILKINSON, Primary Examiner. 

1. IN COMBINATION WITH AN OUTBOARD DRIVE ASSEMBLY OF THE TYPE INCLUDING A DEPENDING POWER LEG HAVING A HORIZONTALLY OUTWARDLY END REARWARDLY PROJECTING CAVITATION FLANGE ADJACENT ITS LOWER END, A DOWNWARDLY AND REARWARDLY PROJECTING EXHAUST OUTLET PROJECTING BELOW THE REAR END PORTION OF SAID CAVITATION FLANGE, A TROLLING MUFFLER ATTACHMENT COMPRISING AN UPSTANDING TUBULAR MEMBER DISPOSED REARWARDLY OF SAID POWER LEG AND TERMINATING AT ITS LOWER END PORTION IN A FORWARDLY OPENING AND DIRECTED OPENING END PORTION SUPPORTINGLY ENGAGED WITH SAID EXHAUST OUTLET AND SAID CAVITATION FLANGE SO AS TO FORM A CONTINUATION OF SAID EXHAUST OUTLET, SAID TUBULAR MEMBER PROJECTING ABOVE THE NORMAL WATER LEVEL ON SAID POWER LEG. 